Cognition, attention altered in youngsters who live with gas appliances.
Morales, E, J Julvez, M Torrent, R de Cid, M Guxens, M Bustamante, N Kunzli and Sunyer. 2009. Association of early-life exposure to household gas appliances and indoor nitrogen dioxide with cognition and attention behavior in preschoolers. American Journal of Epidemiology doi: 10.1093/aje/kwp067.
Pollutants released by gas-powered home appliances may affect a preschooler's mental processes and ability to pay attention.
The effects on memory, verbal skills and the coordination of complex behaviors were greater when more gas appliances were used in the homes. They were also more pronounced in children with a certain gene type involved with the detoxification of toxic exposures.
The study from Spain is the first to look at the effects of indoor air pollution – specifically nitrogen dioxide (NO2) – on cognitive and attention disorders in young children, who generally spend a majority of their early developmental years inside. The increased effects found in children with a specific genetic change is also a novel, but preliminary, result.
A growing number of studies indicate indoor air pollution can affect brain function. Prenatal exposure to air pollutants, including to combustion by-products such as polycyclic aromatic hydrocarbons (PAHs), has been associated with lower scores on scales measuring intellectual development.
The researchers report that children who lived in houses with a gas stove and other gas-fired appliances in use were more likely to exhibit inattention behaviors and scored on average 5 points lower at 4 years of age on a standard battery of tests that measure memory, verbal abilities and motor skills than children living in houses with no gas applicances. Verbal function and executive function – involving the coordination of complex behaviors such as attention and memory – were mostly affected.
The children living in houses with high air concentration of NO2 were found to have lower cognitive abilities and were more likely to have attention problems.
Gas-fueled cooking and heating appliances release NO2, a gas that has been found to damage cells. Even though NO2 was linked to the cognitive and behavioral effects, other unmeasured culprits, such as particulates, may account for the reported effect, the authors note. The butane bottles supplying gas in this part of Spain contain more toxic pollutants than the natural gas used largely to fuel appliances in the U.S. and other parts of the world.
The authors conclude that the "current data provide preliminary evidence that early-life exposure to indoor air pollution from gas appliances may be related to impaired cognitive functioning among preschoolers and may increase their risk of developing ADHD symptoms."
These results were obtained in 398 children whose neurodevelopment was assessed at 4 years of age. Information on the presence of gas appliances was collected and measurements of air NO2 concentrations were performed within the first 3 months of life of study children.
